CH3CHCH\mathrm{CH}_{3} \mathrm{CH} \mathrm{CH}CH3CHCH
CH3CH=CHCH3\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}CH3CH=CHCH3
CH2CH2CHCH2CH_2CH_2CH CH_2CH2CH2CHCH2
CH3CH2CH2CH=CH2CH_3CH_2 CH_2 CH = CH_2CH3CH2CH2CH=CH2